The Maobot is an automated opponent for the card game Mao (a game of many variants, the least confusing perhaps being Mini-Mao).
Basically, you and the Maobot take turns playing cards onto a discard pile - just click the card you want to play - and the first player to empty their hand wins the game.
However, the game begins with a secret rule known only by the Maobot, which determines which card plays are legal, and which aren't. If you play a card which breaks the Maobot's rule, he will alert you to this - you must take the card back, and draw an extra penalty card. (And if either player forfeits their turn because they can't go, then they also have to draw a card.)
As the game progresses, you must - through a process of elimination, deduction, experimentation, superstition and guesswork - work out what the secret rule might be.
At the end of each round, the Maobot will ask if he can make an extra rule up - if you allow it, the next round is played with that rule in effect in addition to the old one. At the end of that round he'll ask again, and then you'll have three rules going. And so on.
The Maobot can also play Bartok and Eights, which are effectively subsets of Mao.
Bartok is played the same as Mao except that the "secret" rules are instead declared aloud, and that the first rule is always "Cards must follow either the suit or the value of the previous card". When the Maobot creates new rules at the ends of rounds, you will be told what they are.
Eights (or Uno) is a static card game that begins with three rules (match suits or values, 2s mean "pick up two", 8s mean "skip a turn), and never changes.
The Guidance Level determines how helpful the Maobot's responses are, when you play an illegal card. The default "Mild" setting will give slightly helpful clues such as "You can't play a club there.". The "Full" setting will explicitly tell you what the rule is that you've broken, and why. The harsh "None" setting will give you no clue at all as to what you've done wrong.
Maobot is either Stupid or Clever; there isn't much difference, and he's always fairly stupid - on the Stupid setting he just plays any card he can, on the Clever setting he looks ahead a couple of moves (blindly assuming that you'll pass, or play very similar cards in return) and chooses a card that he can follow up on the next turn, and (ideally) again on the turn after that. (Of course, the Maobot gets a big advantage from always knowing the rules, and from never playing the wrong card by mistake.)
You can tick the box to Show Maobot's Cards, if you like; it makes for a slightly easier, slightly more scientific game, in that you can see what cards the Maobot is unable to play, whenever he voluntarily passes. And you can see if his AI's as good as yours.
Clicking Start a Fresh Game will erase all of the Maobot's rules and start the game with a new, single rule - it's quite likely that the rules will become overly complicated (or even gridlocked) after five or six rounds, so click this whenever the game becomes boring or jammed, and start again.
Reveal Maobot's Rules will tell you what the Maobot's secret rules are, if it's driving you insane. You can carry on playing the game afterwards.
Normal face-to-face, multiplayer Mao is far more interesting than this one-player exercise - the rule deduction becomes a lot easier (and far more cagey) when you've got x other players being penalised for rule-breaking, and the rules themselves are much more entertaining when completely unlimited in scope ("Anyone playing the four of spades must go and make everyone a drink, or forfeit the game").
Also, in standard Mao the winner of each round gets to make up a new rule for the next one, rather than the same player each time, making the knowledge a lot more uneven and mysterious. Although I would quite like to program a Maobot that would attempt to probabilistically deduce a human's rule, this game restricts all rule creation to the Maobot.
(Oh, and the maximum hand size of ten is only imposed because, well, I didn't bother coding a dynamic, self-hiding maximum hand size. In proper Mao, if you have to draw twenty cards, you have to draw twenty cards.)
The Maobot was largely built as a simple introduction to Mao; getting the principles of the game across in a way that a flat ruleset or description doesn't always manage. If you've enjoyed the simple deduction puzzle aspect of the Maobot, then collar some walking, breathing human beings and unleash a deck of poker cards onto them.
The Maobot knows eleven basic rule types at the moment (click his picture for latest version information); I'll probably add some more at intervals, although most of the best sorts of Mao rules fall far outside of the scope of a one-player structure-limited computer version.